diff --git a/csi.proto b/csi.proto
index bfdc441c..e449e336 100644
--- a/csi.proto
+++ b/csi.proto
@@ -112,7 +112,7 @@ message CreateVolumeRequest {
 
   // The suggested name for the storage space. This field is REQUIRED.
   // It serves two purposes:
-  // 1) Idempotency - This name is generated by the CO to achieve 
+  // 1) Idempotency - This name is generated by the CO to achieve
   //    idempotency. If `CreateVolume` fails, the volume may or may not
   //    be provisioned. In this case, the CO may call `CreateVolume`
   //    again, with the same name, to ensure the volume exists. The
@@ -141,7 +141,7 @@ message CreateVolumeRequest {
   // not supported by the Plugin, the call SHALL fail. This field is
   // REQUIRED.
   repeated VolumeCapability volume_capabilities = 4;
-    
+
   // Plugin specific parameters passed in as opaque key-value pairs.
   // This field is OPTIONAL. The Plugin is responsible for parsing and
   // validating these parameters. COs will treat these as opaque.
@@ -229,7 +229,7 @@ message VolumeCapability {
 // `required_bytes` and `limit_bytes` can be set to the same value. At
 // least one of the these fields MUST be specified.
 message CapacityRange {
-  // Volume must be at least this big. 
+  // Volume must be at least this big.
   uint64 required_bytes = 1;
 
   // Volume must not be bigger than this.
@@ -260,7 +260,7 @@ message VolumeInfo {
 // The total bytes of a serialized VolumeHandle must be less than 1 MiB.
 message VolumeHandle {
   // ID is the identity of the provisioned volume specified by the
-  // Plugin. This field is REQUIRED. 
+  // Plugin. This field is REQUIRED.
   // This information SHALL NOT be considered sensitive such that, for
   // example, the CO MAY generate log messages that include this data.
   string id = 1;
@@ -320,7 +320,7 @@ message ControllerPublishVolumeRequest {
   // The handle of the volume to be used on a node.
   // This field is REQUIRED.
   VolumeHandle volume_handle = 2;
-  
+
   // The ID of the node. This field is OPTIONAL. The CO SHALL set (or
   // clear) this field to match the `NodeID` returned by `GetNodeID`.
   // `GetNodeID` is allowed to omit `NodeID` from a successful `Result`;
@@ -414,7 +414,7 @@ message ValidateVolumeCapabilitiesRequest {
   Version version = 1;
 
   // The information about the volume to check. This is a REQUIRED
-  // field. 
+  // field.
   VolumeInfo volume_info = 2;
 
   // The capabilities that the CO wants to check for the volume. This
@@ -455,10 +455,10 @@ message ListVolumesRequest {
   // returned.
   uint32 max_entries = 2;
 
-  // A token to specify where to start paginating. Set this field to 
+  // A token to specify where to start paginating. Set this field to
   // `next_token` returned by a previous `ListVolumes` call to get the
   // next page of entries. This field is OPTIONAL.
-  string starting_token = 3; 
+  string starting_token = 3;
 }
 
 message ListVolumesResponse {
@@ -469,7 +469,7 @@ message ListVolumesResponse {
 
     repeated Entry entries = 1;
 
-    // This token allows you to get the next page of entries for 
+    // This token allows you to get the next page of entries for
     // `ListVolumes` request. If the number of entries is larger than
     // `max_entries`, use the `next_token` as a value for the
     // `starting_token` field in the next `ListVolumes` request. This
@@ -548,12 +548,12 @@ message ControllerServiceCapability {
       CREATE_DELETE_VOLUME = 1;
       PUBLISH_UNPUBLISH_VOLUME = 2;
       LIST_VOLUMES = 3;
-      GET_CAPACITY = 4; 
+      GET_CAPACITY = 4;
     }
 
     Type type = 1;
   }
-  
+
   oneof type {
     // RPC that the controller supports.
     RPC rpc = 1;
@@ -568,7 +568,7 @@ message NodePublishVolumeRequest {
   // The handle of the volume to publish. This field is REQUIRED.
   VolumeHandle volume_handle = 2;
 
-  // The CO SHALL set this field to the value returned by 
+  // The CO SHALL set this field to the value returned by
   // `ControllerPublishVolume` if the corresponding Controller Plugin
   // has `PUBLISH_UNPUBLISH_VOLUME` controller capability, and SHALL be
   // left unset if the corresponding Controller Plugin does not have
@@ -612,7 +612,7 @@ message NodeUnpublishVolumeRequest {
   // The handle of the volume. This field is REQUIRED.
   VolumeHandle volume_handle = 2;
 
-  // The path at which the volume was published. It MUST be an absolute 
+  // The path at which the volume was published. It MUST be an absolute
   // path in the root filesystem of the process serving this request.
   // This is a REQUIRED field.
   string target_path = 3;
@@ -640,10 +640,10 @@ message GetNodeIDRequest {
 
 message GetNodeIDResponse {
   message Result {
-    // The ID of the node which SHALL be used by CO in 
+    // The ID of the node which SHALL be used by CO in
     // `ControllerPublishVolume`. This is an OPTIONAL field. If unset,
     // the CO SHALL leave the `node_id` field unset in
-    // `ControllerPublishVolume`. 
+    // `ControllerPublishVolume`.
     NodeID node_id = 1;
   }
 
@@ -699,7 +699,7 @@ message NodeServiceCapability {
 
     Type type = 1;
   }
-  
+
   oneof type {
     // RPC that the controller supports.
     RPC rpc = 1;
@@ -841,7 +841,7 @@ message Error {
       // retrying.
       INVALID_PARAMETER_VALUE = 7;
     }
-    
+
     // Machine parsable error code.
     CreateVolumeErrorCode error_code = 1;
 
@@ -900,7 +900,7 @@ message Error {
       // succeeded.
       VOLUME_DOES_NOT_EXIST = 4;
     }
-    
+
     // Machine parsable error code.
     DeleteVolumeErrorCode error_code = 1;
 
@@ -1007,7 +1007,7 @@ message Error {
       // retrying.
       INVALID_NODE_ID = 8;
     }
-    
+
     // Machine parsable error code.
     ControllerPublishVolumeErrorCode error_code = 1;
 
@@ -1098,7 +1098,7 @@ message Error {
       // retrying.
       NODE_ID_REQUIRED = 8;
     }
-    
+
     ControllerUnpublishVolumeErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1136,7 +1136,7 @@ message Error {
       // retrying.
       INVALID_VOLUME_INFO = 5;
     }
-    
+
     ValidateVolumeCapabilitiesErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1190,7 +1190,7 @@ message Error {
       // retrying.
       INVALID_VOLUME_HANDLE = 7;
     }
-    
+
     NodePublishVolumeErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1241,7 +1241,7 @@ message Error {
       // retrying.
       INVALID_VOLUME_HANDLE = 4;
     }
-    
+
     NodeUnpublishVolumeErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1262,7 +1262,7 @@ message Error {
       BAD_PLUGIN_CONFIG = 1;
       MISSING_REQUIRED_HOST_DEPENDENCY = 2;
     }
-    
+
     ProbeNodeErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1282,7 +1282,7 @@ message Error {
       BAD_PLUGIN_CONFIG = 1;
       MISSING_REQUIRED_HOST_DEPENDENCY = 2;
     }
-    
+
     GetNodeIDErrorCode error_code = 1;
     string error_description = 2;
   }
diff --git a/spec.md b/spec.md
index 4d486096..e830c093 100644
--- a/spec.md
+++ b/spec.md
@@ -407,7 +407,7 @@ message CreateVolumeRequest {
 
   // The suggested name for the storage space. This field is REQUIRED.
   // It serves two purposes:
-  // 1) Idempotency - This name is generated by the CO to achieve 
+  // 1) Idempotency - This name is generated by the CO to achieve
   //    idempotency. If `CreateVolume` fails, the volume may or may not
   //    be provisioned. In this case, the CO may call `CreateVolume`
   //    again, with the same name, to ensure the volume exists. The
@@ -436,7 +436,7 @@ message CreateVolumeRequest {
   // not supported by the Plugin, the call SHALL fail. This field is
   // REQUIRED.
   repeated VolumeCapability volume_capabilities = 4;
-    
+
   // Plugin specific parameters passed in as opaque key-value pairs.
   // This field is OPTIONAL. The Plugin is responsible for parsing and
   // validating these parameters. COs will treat these as opaque.
@@ -524,7 +524,7 @@ message VolumeCapability {
 // `required_bytes` and `limit_bytes` can be set to the same value. At
 // least one of the these fields MUST be specified.
 message CapacityRange {
-  // Volume must be at least this big. 
+  // Volume must be at least this big.
   uint64 required_bytes = 1;
 
   // Volume must not be bigger than this.
@@ -555,7 +555,7 @@ message VolumeInfo {
 // The total bytes of a serialized VolumeHandle must be less than 1 MiB.
 message VolumeHandle {
   // ID is the identity of the provisioned volume specified by the
-  // Plugin. This field is REQUIRED. 
+  // Plugin. This field is REQUIRED.
   // This information SHALL NOT be considered sensitive such that, for
   // example, the CO MAY generate log messages that include this data.
   string id = 1;
@@ -638,7 +638,7 @@ message ControllerPublishVolumeRequest {
   // The handle of the volume to be used on a node.
   // This field is REQUIRED.
   VolumeHandle volume_handle = 2;
-  
+
   // The ID of the node. This field is OPTIONAL. The CO SHALL set (or
   // clear) this field to match the `NodeID` returned by `GetNodeID`.
   // `GetNodeID` is allowed to omit `NodeID` from a successful `Result`;
@@ -754,7 +754,7 @@ message ValidateVolumeCapabilitiesRequest {
   Version version = 1;
 
   // The information about the volume to check. This is a REQUIRED
-  // field. 
+  // field.
   VolumeInfo volume_info = 2;
 
   // The capabilities that the CO wants to check for the volume. This
@@ -801,10 +801,10 @@ message ListVolumesRequest {
   // returned.
   uint32 max_entries = 2;
 
-  // A token to specify where to start paginating. Set this field to 
+  // A token to specify where to start paginating. Set this field to
   // `next_token` returned by a previous `ListVolumes` call to get the
   // next page of entries. This field is OPTIONAL.
-  string starting_token = 3; 
+  string starting_token = 3;
 }
 
 message ListVolumesResponse {
@@ -815,7 +815,7 @@ message ListVolumesResponse {
 
     repeated Entry entries = 1;
 
-    // This token allows you to get the next page of entries for 
+    // This token allows you to get the next page of entries for
     // `ListVolumes` request. If the number of entries is larger than
     // `max_entries`, use the `next_token` as a value for the
     // `starting_token` field in the next `ListVolumes` request. This
@@ -905,12 +905,12 @@ message ControllerServiceCapability {
       CREATE_DELETE_VOLUME = 1;
       PUBLISH_UNPUBLISH_VOLUME = 2;
       LIST_VOLUMES = 3;
-      GET_CAPACITY = 4; 
+      GET_CAPACITY = 4;
     }
 
     Type type = 1;
   }
-  
+
   oneof type {
     // RPC that the controller supports.
     RPC rpc = 1;
@@ -938,7 +938,7 @@ message NodePublishVolumeRequest {
   // The handle of the volume to publish. This field is REQUIRED.
   VolumeHandle volume_handle = 2;
 
-  // The CO SHALL set this field to the value returned by 
+  // The CO SHALL set this field to the value returned by
   // `ControllerPublishVolume` if the corresponding Controller Plugin
   // has `PUBLISH_UNPUBLISH_VOLUME` controller capability, and SHALL be
   // left unset if the corresponding Controller Plugin does not have
@@ -997,7 +997,7 @@ message NodeUnpublishVolumeRequest {
   // The handle of the volume. This field is REQUIRED.
   VolumeHandle volume_handle = 2;
 
-  // The path at which the volume was published. It MUST be an absolute 
+  // The path at which the volume was published. It MUST be an absolute
   // path in the root filesystem of the process serving this request.
   // This is a REQUIRED field.
   string target_path = 3;
@@ -1033,10 +1033,10 @@ message GetNodeIDRequest {
 
 message GetNodeIDResponse {
   message Result {
-    // The ID of the node which SHALL be used by CO in 
+    // The ID of the node which SHALL be used by CO in
     // `ControllerPublishVolume`. This is an OPTIONAL field. If unset,
     // the CO SHALL leave the `node_id` field unset in
-    // `ControllerPublishVolume`. 
+    // `ControllerPublishVolume`.
     NodeID node_id = 1;
   }
 
@@ -1108,7 +1108,7 @@ message NodeServiceCapability {
 
     Type type = 1;
   }
-  
+
   oneof type {
     // RPC that the controller supports.
     RPC rpc = 1;
@@ -1256,7 +1256,7 @@ message Error {
       // retrying.
       INVALID_PARAMETER_VALUE = 7;
     }
-    
+
     // Machine parsable error code.
     CreateVolumeErrorCode error_code = 1;
 
@@ -1315,7 +1315,7 @@ message Error {
       // succeeded.
       VOLUME_DOES_NOT_EXIST = 4;
     }
-    
+
     // Machine parsable error code.
     DeleteVolumeErrorCode error_code = 1;
 
@@ -1422,7 +1422,7 @@ message Error {
       // retrying.
       INVALID_NODE_ID = 8;
     }
-    
+
     // Machine parsable error code.
     ControllerPublishVolumeErrorCode error_code = 1;
 
@@ -1513,7 +1513,7 @@ message Error {
       // retrying.
       NODE_ID_REQUIRED = 8;
     }
-    
+
     ControllerUnpublishVolumeErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1551,7 +1551,7 @@ message Error {
       // retrying.
       INVALID_VOLUME_INFO = 5;
     }
-    
+
     ValidateVolumeCapabilitiesErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1605,7 +1605,7 @@ message Error {
       // retrying.
       INVALID_VOLUME_HANDLE = 7;
     }
-    
+
     NodePublishVolumeErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1656,7 +1656,7 @@ message Error {
       // retrying.
       INVALID_VOLUME_HANDLE = 4;
     }
-    
+
     NodeUnpublishVolumeErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1677,7 +1677,7 @@ message Error {
       BAD_PLUGIN_CONFIG = 1;
       MISSING_REQUIRED_HOST_DEPENDENCY = 2;
     }
-    
+
     ProbeNodeErrorCode error_code = 1;
     string error_description = 2;
   }
@@ -1697,7 +1697,7 @@ message Error {
       BAD_PLUGIN_CONFIG = 1;
       MISSING_REQUIRED_HOST_DEPENDENCY = 2;
     }
-    
+
     GetNodeIDErrorCode error_code = 1;
     string error_description = 2;
   }